[AD] odd problem with WindowsXP + allegro

["Javier Gonzalez" <Xavier_Gonzalez@xxxxxxxxxx>]

Using winxp pro + sp1, latest drivers of nvidia geforce 2 mx400, alleg
4.1.3, msvc6 + sp5

I just noticed that all the programs that dont update the screen usually
(say for example extruec and others) show the screen fine but change it
oddly after 3 secs or so... Something very odd...

This isn't noticeable on programs that update the screen all the time tho

Screenshot of the alfont example program in the second 0 of running
 http://raythe.sytes.net/TheDeath/one.jpg
that same screen 3 secs after
 http://raythe.sytes.net/TheDeath/two.jpg

In case you are wondering that program simply prints the text on screen and
waits for the user to press a key to exit, nothing else.

Note this problem only happens in fullscreen

Any ideas? Anybody else with winxp having this problem?